Routing in FL Studio: buses, sends, sidechain, pre/post fader

Mixer structure

• The FL Studio mixer has the Master, many Insert tracks (up to 125 in recent versions) and the Current track. Each track has 10 effect slots (each with its own dry/wet mix control), Pan, Stereo separation, a volume fader, polarity inversion, L/R swap, disk recording arming and the routing section at the bottom.
• By default every Insert track is routed to the Master.
• Every Channel Rack channel (generator or sample) must be linked to a mixer track: the "Mixer track" field in the channel settings (the number at the top right of the Channel Rack) or by selecting the channels and the mixer track and using the link shortcut (Ctrl+L; check the manual for the variants that link several channels to consecutive tracks or to a single track). Leaving channels on the Master track prevents you from processing them individually.
• Multi-output plugins (FPC, Kontakt, drum machines): assign each output to a different mixer track to process kick, snare, etc. separately.

Routes and sends

1. Select the source track (click on its name).
2. On the destination track, an arrow (the route connector) appears at the bottom: left-click to create the link. A send level knob appears on the link.
3. Right-click the arrow → "Route to this track only": creates the link and removes the one to the Master (typical for buses: tracks go to the bus, the bus goes to the Master).
4. "Sidechain to this track": a modulation-only link: the signal reaches the sidechain inputs of the plugins on the destination track, but is not added to the audio (see "Sidechain").
5. The mixer's built-in sends take the signal after the effects and after the fader of the track (post-fader): if you lower the vocal fader, the amount reaching the reverb drops too.
6. Pre-fader send: insert Fruity Send in a slot of the source track: it picks up the signal at that point in the effects chain, before the fader. Link the source track to the destination with "Sidechain to this track", then choose the destination in "Send to"; Volume and Pan adjust the sent signal, Dry controls what passes through on the channel (0% by default). You need one Fruity Send per destination; it can't be used on the Master or to create feedback.
7. Frequency Splitter can send different bands to different tracks; its sends are pre-fader (watch out for doubled signal: use sidechain links, mute the main outputs or lower the fader).
8. Transmitter can send transient and sustain to different tracks (sidechain outputs).

Recommended architecture

Consistent colors and names (e.g. drums red, bass orange, music green, vocals blue, effects purple) speed up your work.

Pre- or post-fader: when

• Post-fader (standard sends): reverbs and delays for the mix. The dry/wet ratio stays constant when you change the volume.
• Pre-fader (Fruity Send): when you want the effect to continue even when you lower the source (reverb that remains after you "close" the vocal, effect-only signal, parallel processing that must stay independent of the fader), or to send a signal from a specific point in the chain (e.g. before saturation).

Sidechain

• Source (kick or ghost kick) → destination with "Sidechain to this track"; in the destination plugin (Fruity Limiter, Fruity Compressor, Pro-C 2, Pro-Q, LuxeVerb Envelope, Transmitter) choose the sidechain input that matches the source track.
• Fruity Peak Controller doesn't need audio routing: it follows the level of the track it is inserted on and connects to parameters with "Link to controller".

Latency and compensation

FL Studio automatically compensates for the latency reported by plugins (linear-phase EQs, lookahead limiters, pitch shifters). If a plugin doesn't report it correctly, parallel tracks can drift out of phase (comb filtering): check by aligning the waveforms or with correlation, and in extreme cases set the compensation manually in the mixer track properties.

Patcher

Patcher lets you build internal chains with free routing (band splitting, parallel, M/S, macros): useful for complex chains you want to reuse as presets (e.g. "Vocal chain" or "Multiband 808").

Solo, mute and listening

• Solo on a track in FL keeps the tracks routed to/from it audible (e.g. soloing the drum bus = you hear the whole drum kit): useful for listening to a group.
• Mute buses for quick comparisons (with and without vocals, with and without effects).

Common mistakes

• Tracks routed to both the bus and the Master (doubled signal, wrong levels): always use "Route to this track only" for buses.
• Channel Rack channels left on the Master.
• Reverbs as inserts instead of sends.
• Ghost kick ending up in the Master (doubled kick).
• Parallel processing with uncompensated latency.
• Mastering chain on the Master while you listen to references through the same output.

How to verify

• Mute the bus's Master route: the whole group should disappear; if anything remains, it's routed incorrectly.
• Lower the fader of a source: post-fader sends should go down, pre-fader ones should not.